In an electronic drum which is a kind of conventional electronic percussion musical instruments, the vibrations caused by striking the pad surface or the rim of the electronic drum are detected by the sensor provided under the pad or on the rim, and the detection output signals trigger the generation of musical tones for drum sounds. A conventional electronic drum comprises, as shown in unexamined Japanese patent publication No. H6-175651, a shallow pan-shaped body frame made of hard rubber or the like material and a baseplate made of iron and fixed to the bottom of the body frame, the body frame and the baseplate being together supported by a base member. In the pad rubber constituting the strike surface is embedded a pad plate, which in turn is supported by the baseplate by means of a cushion member in a doughnut (ring) shape. On the under surface of the pad plate is attached a pad sensor. In the peripheral area of the body frame is embedded a rim plate with a rim sensor attached to the inner wall of the rim plate. When a player strikes the pad rubber of the electronic drum of the above-mentioned structure, the pad plate vibrates and the vibration will be detected or picked up by the pad sensor. When the player gives a rim shot, the rim plate vibrates upon strike on the rim by the player, and the vibration will be detected by the rim sensor. In this structure, the pad plate is not in direct contact with the rim, but in indirect contact with the rim via the pad rubber, in which the pad rubber attenuates the propagation therethrough of the vibration from the rim, as the pad rubber is made of a rubber material which is softer than the rubber of the rim. Thus, the vibration of the rim plate will not reach the pad sensor. Consequently, the pad sensor and the rim sensor separately detects the respective vibrations as electric signals, which in turn pass through the electric circuit, the amplifier and the loudspeaker to be amplified electrically and emitted as musical sounds.
In such an electronic drum of a conventional structure, however, when external noises (disturbances) of vibration are transmitted from the floor or else to the base member, the vibration of the base member will not propagate through the cushion member to the pad plate, being absorbed in the cushion member. On the other hand, as the rim is made integral with the body frame which is directly supported by the base member, the disturbing noise vibrations transmitted to the base member will be further transmitted to the body frame and the rim and will be detected or picked up by the rim sensor. Such has been a drawback with the conventional electronic drum.